22 Winchester Magnum Rimfire Rifle Cartridge: The .22 Winchester Magnum Rimfire was introduced in the 1950s by Winchester, and it was the only successful rimfire cartridge introduced in the 20th century as it was quickly chambered in handguns and rifles. The .22 Magnum when chambered in a rifle gives its users many oppurtunities for a wide selection of ammunition.

Hornady with its great success in smaller rimfire calibers took a look at the .22 Magnum and decided that they could offer ammunition superior to factory 40 grain bullet loadings. The strength of the .22 Magnum casing allows for higher pressure levels, what was needed were some lighter bullets for a flatter trajectory.

On the other end of the .22 Magnum spectrum would be a possibly slightly heavier bullet designed for deeper penetration with excellent expansion qualities as well. Hornady filled in these gaps with their new .22 magnum ammunition line.